[mvapich-discuss] Cannot utilize CPU core

[MORRIS LAW]

Dear all,

I am new to the discussion group.

Recently I found a problem of running mvapich 1.1 on Gen2-IB device (Qlogic 9120).  When subsequent run of mvapich job was delivered to the nodes, the later jobs will not run on free CPU cores but will compete with the current running CPU cores.  Thus the whole node cannot be utilized.  I don't know where the problem is.  Is it related to the IB switch or some parameter when I built the mvapich 1.1?

I built mvapich 1.1 using gcc 4.1 on CentOS 5.3.  I have also built another version of mvapich 1.1 using icc and ifort on the same CentOS 5.3.  Both run jobs having similar problem.

Would someone give me some hints to tackle the problem? 

Thanks in advance.

--
Morris Law
HK Baptist University